Abstract This application is for a NIH Support for Conferences and Scientific Meetings (R13) award to support a FASEB meeting on Mobile DNA in Mammalian Genomes. This is a meeting that recurs every two years, gathering a collegial group of distinguished researchers for five-day information exchange. It provides both scientific content and professional opportunities for trainees and new investigators in the field. Advances in nucleic acid sequencing have underscored that mobile elements are active in our genomes continue to be one of the major intrinsic sources of structural variation and genetic instability. With respect to human cancers, there is increasing appreciation that many tumor types show hypomethylation of these repetitive DNAs, express protein products coded by these sequences, and provide a cellular environment permissive of new genomic integrations of mobile DNAs. This meeting spans sequence analysis, comparative genomics and evolutionary biology, cancer genetics, as well as functional assays and the discovery of new activities associated with mobile elements. It is critical that investigators have an opportunity to get together to immerse themselves in this complex field, and it is particularly important for young investigators, and those moving into the field to attend meetings such as this one, in order that they fully appreciate technical challenges posed by these high copy number repeats. Our specific aims are : 1. To share the latest biology and techniques regarding mobile elements with investigators in the field. 2. To accelerate the development of young scientists in the field. 3. To facilitate future collaboration and communication among members of the field.